Cartridge fuse holder with indicator



March 16, 1965 E. BORYS 3,174,011

CARTRIDGE FUSE HOLDER WITH INDICATOR Filed Sept. 25. 1961 &

INVEN TOR.

BY [72d 502:9? W li United States Patent 3,174,011 CARTRIDGE FUE HOLDER WlTfll INDICATOR Emil Borys, 710 (lid Rand Road, Lake Zurich, lll. Filed Sept. 25, 12 61, Ser. No. 140,23) 6 Claims. (Cl. 280 121) This invention relates generally to innovations and improvements in cartridge fuse holders provided with glow lamps which become energized and glow only when the cartridge fuse for a particular holder blows.

Cartridge fuse holders of this general type, but without indicating glow lamps, are generally known. They are of the type designed to be mounted in large numbers on one side of a panel with electrically conductive bolts or other types of fasteners projecting through the panel and providing terminals for wiring or circuitry on the rear side of the panel.

Ordinarily, when one of the cartridge fuses held by such conventional holders blows, it is necessary to carefully check each fuse on the panel until the one that is blown is spotted. Thus, it is not ordinarily possible to pick out the blown fuse from a large group of fuses, merely by glancing at the group. Once the blown fuse has been discovered it may be readily replaced. However, as much as several minutes may be consumed in selecting the blown fuse, depending upon the complexity of the fuse panel, the lighting, etc. In many instances this shut-down time is very objectionable and costly, particularly where it involves the interruption of important procedures or equipment, as is often the case.

The object of this invention, generally stated, is the provision of cartridge fuse holders of the type described for holding cartridge fuses in exposed position, with each such holder being provided with a self-contained glow lamp circuit which is energized only when the associated cartridge fuse is blown.

An important object of the invention is the provision of such fuse holders which are inexpensive to manufacture on a quantity production basis from inexpensive components, and which are safe and reliable in use.

Certain other objects of the invention will, in part, be obvious and will in part appear hereinafter.

For a more complete understanding of the nature and scope of the invention reference may now be had to the following detailed description thereof taken in connection with the accompanying drawings wherein:

FIG. 1 is a side elevational view of a cartridge fuse holder constituting one embodiment of the present invention;

FIG. 2 is an end-elevational view of the fuse holder shown in FIG. 1 taken on line 2-2 thereof;

FIG. 3 is a top plan view of the fuse holder shown in FIG. 1;

FIG. 4 is a bottom plan view of the fuse holder shown in FIG. 1;

FIG. 5 is a bottom plan view of the fuse holder shown in FIG. 1 with the closure plate being removed and showing the glow lamp on the interior;

FIG. 6 is an enlarged transverse sectional view taken on line 6-6 of FIG. 1; and

FIG. 7 is a longitudinal view taken on line 77 of FIG. 3.

Referring now to the drawings, the cartridge fuse holder in its entirety is indicated at T0 and comprises a rectangular mounting box 11 supporting a pair of car 3,174,011 Patented Mar. 16,- 1965 tridge fuse contact holders 12 and 13. Each of the contact holders l2 and 13 is of conventional construction being stamped and formed from a springy conductive material such as copper. Each of the clip contacts 12 and 13 is U-shaped with a fiat bottom as shown in FIGS. 2 and 6 with the upstanding legs being provided with outwardly bowed conformations 14-14 for receiv ing the terminal caps of the cartridge fuses. Proper longitudinal positioning of the cartridge fuses is provided by the inwardly bowed portions 1.5-4.5.

The terminal mounting box 11 for the clip terminals 12 and 13 is formed of a dielectric material, preferably a plastic material that can be injection molded on a quantity production basis. Polystyrene forms a suitable material for this purpose but other materials that can be used include phenol formaldehyde resins, polyethylene, methyl-methacrylate, etc. The mounting box 11 comprises a main box portion 16 (FIG. 6) provided with a closure plate 17 which can be friction fitted into place. Desirably, the top panel or wall of the main portion 16 is provided with a raised or thickened center portion indicated at 13 in FIG. 1, with the opposite ends thereof providing transverse aligning edges l919 for the contact clips 12 and 13. These aligning edges facilitate the ready installation of the contact clips on a quantity product-ion basis.

Each of the clips 12 and 13 is secured in place by means of a readily installed fastener arrangement shown best in FIG. 6. There is disclosed in FIG. 6 a hollow, interiorly threaded rivet member 20 of known type having at the top a head 21 in the form of an integral flange which rests on the top of the yolk portion of its associated clip 12 and secures it in place. The hollow rivets 20 are installed by known power driven setting tools which places them under longitudinal compression toward their heads so as to bulge them out at the weakened intermediate portions indicated at 22, thereby permanently securing the rivets in place. Before the hollow rivets 20 are drawn or set in this manner, flat washer terminals 23 and 24- a-re placed over each so as to be permanently secured in place on the underside of the top panel portion of the box 16 while being locked above the bulged portions 22. The length of the hollow rivet members 20 is such that after they are set or drawn the bottom ends thereof are even with, or slightly shorter than the lower edges of the box 16. The closure panel 17 is provided with two openings whereby it can be slipped over each of the hollow rivets 20. It will be understood that the clip terminal 13 is secured in place in the same manner as the clip terminal 12.

Referring to FIG. 5, each of the washer terminals 23 and 24 is provided with a projecting flat tab 25 and 26 respectively to which electrical connections may be readily made. On the interior, the box 16 is provided with three integrally formed post-like members which serve to position and cage in a miniature neon glow lamp 27 of known type. This glow lamp is so positioned that it can be readily seen through the slot-like opening 28 (FIG. 3) in the top panel of the box 16. The three post like members are indicated in FIG. 5 at 30, 31 and 32. The post 34} is integrally formed so as to project both inwardly from the adjacent side wall of box 16 and downwardly from the top panel thereof. The post 31 is also elongated but aligned at right angles to the post 30 and parallel to the box side wall. The post 31 projects integrally downwardly from the top panel of the box 16. The glow lamp 27 is placed in the box 16 so that the tip end abuts against the post with the main body of the lamp being lightly wedged in between the side wall and the retaining post 31. Proper positioning of the glow lamp 27 is further provided by means of the circular post like member 32 projecting integrally downwardly from the top panel and in between the terminals of the glow lamp. It will be understood that the posts 3t 31 and 32 may be integrally molded at the same time the box member 16 is molded so as not to increase the cost thereof. ()ne terminal of the glow lamp 27 is connected by means of a conductor 33 to the terminal tab 25 while the other terminal of the glow lamp is connected by means of a short conductor 34 to one terminal of a miniature resistor 35. The opposite terminal of the resistor is connected by means of a short conductor 36 to the terminal tab 26.

It will be seen that when a cartridge fuse is in place in the fuse holder with its terminals secured in the clips 12 and 13, the fuse element will be in parallel circuit relationship with the glow lamp circuit 27 on the interior of the box 16 which includes: the fiat washer 23; terminal tab 25; conductor 33; glow lamp 27; conductor 32; resistor 35; conductor 36; terminal tab as; and, flat washer 24. It will of course be appreciated that the washer 23 is directly shorted to the clip 12 while the washer 24 is directly shorted to the clip 13, by means of the hollow rivets 26. Because of the much lower resistance of the fuse elements of the cartridge fuses in comparison with the high resistance of the glow lamp circuits, as long as each cartridge fuse element remains intact, the current will flow through the fuse element. lowever, if for any reason a fuse is blown, then its glow lamp circuit becomes energized and the particular lamp or bulb 27 will glow or light up so that it can be readily seen from a distance through the window 28.

It will be appreciated that each of the fuse holders it) may be readily secured in place on a mounting panel by means of a pair of bolts or screws extending through each of the interiorly threaded, hollow rivet members 2%). The various terminals can be connected to the rearwardly projecting ends of the bolts 4% so that the various circuits are properly fused. It is easy to pick out the fuse which is blown even when there are a large number of the fuse holders lit} compactly arranged side by side in vertical and horizontal rows. One simply has to notice the fuse holders in which the glow lamps are energized and the blown cartridge fuses are removed from them and are replaced by fresh fuses whereupon the glow lamps go out.

The fuse holders lit) are of a design which permits them to be inexpensively, but reliably, manufactured on a quantity production basis at low cost. The terminal clips 12 and 13 are standard items which can be purchased at low unit cost. Likewise, the tubular rivets 3f the washer terminals 23 and 24, the glow lamps 27 and the resistors 35 are all standard items available at low cost. The hollow box member 12 and the cover or bottom plate 17 are inexpensively produced as mentioned, the hollow box member 16 being injection molded in a multiple cavity mold, while the closing panels 17 are stamped out from flat stock.

In the manufacture of the fuse holders It), the glow lamp sub-assemblies are separately made, each comprising a glow lamp 27, a resistor 35, and the associated conductors. It will be'seen that it is a simple matter to first secure each of the clips 12 and 13 in place with the washer terminals 23 and 24 being locked under the bulges 22 formed in-the tubular rivets 20 when they are set. It is then a simple matter to insert each glow lamp 27 in its place within the posts 3%, 31 and 32, whereupon connector 33 is soldered to the tab 25 while the connector 35 is soldered to the tab 26.

Having described a preferred embodiment of the invention, includin the technique of producing it on a quantity production basis, what is claimed as new is:

l. A cartridge fuse mounting holder comprising, a mounting box formed of dielectric material and having a window formed in the top panel thereof, a pair of clip contacts mounted on opposite ends of the top panel of said box and aligned to retain a cartridge fuse therebetween with each cap terminal thereof being held in one of said clip contacts, electrically conductive hollow fastener means securing each of said clip contacts in place on said top panel and projecting down into said mounting box, a glow lamp disposed within said box so as to be visible through said window, conductors interconnecting said glow lamp in circuit relationship with fastener means within said box and second electrically conductive fastener means extending through said hollow fastener means and serving to mount said holder.

2. A cartridge fuse mounting holder comprising, a mounting box formed of dielectric material and having a slot window formed in the top panel thereof, a pair of spring clip electrical contacts mounted on opposite ends of the top panel of said box and aligned to retain a cartridge fuse therebetween with each cap terminal thereof being clipped in one of said contacts, electrically conductive fastener means for each contact in the form of a metallic hollow rivet with the head thereof retainingly engaging its associated contact and with the tubular shank portion thereof projecting into said box, a two-terminal glow lamp mounted within said box so as to be visible through said window, a resistor within said box, conductors connecting said glow lamp and resistor in series circuit relationship with said tubular shank portions of said rivets, and second electrically conductive fastener means extending through said hollow rivets and serving to mount said holder.

3. A cartridge fuse mounting holder comprising, a mounting box formed of dielectric material having a slot window formed in the top panel thereof adjacent one of the sides, a pair of U-shaped spring clip electrical contacts mounted on opposite ends of the top panel of said box out of alignment with said window and aligned with each other so as to retain a cartridge fuse thercbetween with each end cap terminal thereof being clipped within one of said contacts, the yoke portions of said contacts being fiat, fastener means for each contact in the form of a hollow interiorly threaded rivet having a flanged head portion which retainingly engages the yoke portion of its associated contact and a hollow shank portion within said box with a weakened collapsible section, a tabbed washer terminal fitting over each of said hollow shanks and firmly retained against the underside of said top panel by the outwardly bulged collapsed section, glow lamp retaining posts integrally formed on the inside of said box with two of them located at opposite ends of said slot window and with the third being located along the side of said window opposite the adjacent side wall of said box, a two-terminal glow lamp disposed within said retaining posts and adjacent the underside of said top panel so as to be viewable through said window, a two-terminal resistor, a first conductor connecting one terminal of said glow lamp with one terminal of said resistor, a second conductor connecting the second terminal of said glow lamp with the tab on one of said tabbed washer terminals, and a third conductor connecting the second terminal of said resistor with the tab on the other of said tabbed washer terminals.

4. The cartridge fuse mounting holder of claim 3 wherein the outer surface of said top panel has a raised intermediate portion providing aligning ridges for aligning each of said contacts.

5. The cartridge fuse mounting holder of claim 3 wherein said glow lamp is wedged into place directly under said slot window by said retaining posts.

6. The cartridge fuse mounting holder of claim 3 wherein said box is open-sided at the bottom and closed 5 by a friction fitting p1ate provided with apertures in registration with said tubular rivet shanks.

References Cited in the file of this patent UNITED STATES PATENTS 5 1,951,310 La Ma-r Mar. 13, 1934 1,957,546 La Mar May 8, 1934 6 La Mar Jan. 29, 1935 Wood Jan. 12, 1943 Linton Dec. 27, 1-949 Sundt Feb. 26, 1957 Linton Sept. 9, 1958 FOREIGN PATENTS Australia June 10, 1954 

1. A CARTRIDGE FUSE MOUNTING HOLDER COMPRISING, A MOUNTING BOX FORMED OF DIELECTRIC MATERIAL AND HAVING A WINDOW FORMED IN THE TOP PANEL THEREOF, A PAIR OF CLIP CONTACTS MOUNTED ON OPPOSITE ENDS OF THE TOP PANEL OF SAID BOX AND ALIGNED TO RETAIN A CARTRIDGE FUSE THEREBETWEEN WITH EACH CAP TERMINAL THEREOF BEING HELD IN ONE OF SAID CLIP CONTACTS, ELECTRICALLY CONDUCTIVE HOLLOW FASTENER MEANS SECURING EACH OF SAID CLIP CONTACTS IN PLACE ON SAID TOP PANEL AND PROJECTING DOWN INTO SAID MOUNTING 